Wind power is a growing form of renewable energy which is appealing because it does not consume any fuel or require any rare materials. Wind farms use turbines to transform the energy contained in wind into electrical power. The process is mechanically driven and has no byproducts. This allows low maintenance costs and favorable amounts of environmental impact. The worldwide wind power capacity has shown a rapidly increasing trend over the past several years, representing a growing proportion of the world's renewable energy production.
In recent years, wind power has become an increasing portion of the world's renewable energy usage. Worldwide, there were 200 gigawatts of wind capacity installed by the end of 2010. In comparison, only 40 gigawatts of solar power capacity were installed by that time.  The worldwide wind capacity had increased by 25% from 2009 to 2010, while the worldwide consumption of renewable energy had only increased by 15%, signifying a growth of wind power relative to other renewable resources.  The growth of the wind industry has been especially rapid in China, which reportedly grew from 16% to 22% of the world's installed wind capacity during 2010.  A study within the European Union reported a total wind power production of 131 terawatt-hours in 2009 - about 4% of the total electricity production of 3300 terawatt-hours in those countries. [1,2]
The steady development of higher capacity wind turbines and power lines has allowed the construction of larger wind farms around the world. China has stated its intentions to develop 100 gigawatts of wind power capacity by 2020, including a currently under-construction 20-gigawatt wind base.  In comparison, the largest wind farm worldwide by 2009 was the 781.5 megawatt Roscoe wind farm in Texas.  Other countries have also been developing their wind power, resulting in the nearly 25% global increase in wind power capacity in 2010. 
One of the most attractive features of wind farms is that after their initial construction cost, they cost relatively little to maintain. Approximately 76% of the cost of a wind farm goes into building the turbines, with most of the remainder going toward the turbine foundations and connections to the power grid.  A recent estimate placed the investment cost of a wind farm between $1300 and $1700 per kilowatt, mostly for the turbines.  Various studies have placed operation and management costs of the wind farms at five cents or less per kilowatt-hour, with newer, larger turbines costing as little as a cent per kilowatt-hour to maintain.  In comparison, oil at a cost of about $80 per barrel costs five cents per kilowatt-hour.  Thus, a wind farm that is operated for long enough can produce more energy per cost than oil.
Wind power promises many fewer adverse environmental effects compared to conventional power plants. Since wind power does not require burning fossil fuels, carbon dioxide emissions are improved by incorporating more wind-generated power into the grid while reducing the use of fuel-consuming energy sources. Also, building a large wind farm does not necessarily prevent that land from being used for agriculture; turbines only take up a small portion of the land space on a wind farm, and the rest of the land may be used for other purposes.
The wind power industry is rapidly growing worldwide. The promise of a clean, renewable energy source with low maintenance costs has caused the world's industrial leaders to increasingly invest in wind projects in recent years. As wind projects continue to be completed with ever increasing power capacities, a larger proportion of the world's electric power needs will be provided by this clean power source.
© Michael Shu. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 "BP Statistical Review of World Energy 2011," British Petroleum, June 2011.
 "The State of Renewable Energies in Europe," Observ'ER, December 2010.
 E. Chen, "China Starts Building First 10-GW Mega Wind Farm," Reuters, 8 August 2009.
 E. O'Grady, "E.ON Completes World's Largest Wind Farm in Texas," Reuters, 1 October 2009.
 European Wind Energy Association, Wind Energy - The Facts (Routledge, 2009).